micturáció

Micturition, also known as urination or voiding, is the process by which a mammal expels urine from the bladder. This physiological function is essential for the removal of metabolic waste products and excess fluid from the body. The process involves a coordinated action of the urinary bladder, the urethral sphincters, and the nervous system.

The bladder is a muscular organ that stores urine produced by the kidneys. As the bladder fills, stretch receptors in its walls send signals to the brain, indicating the need to urinate. This sensation typically begins when the bladder is about half full. When the urge becomes strong enough, voluntary control over the external urethral sphincter is relaxed.

The internal urethral sphincter, a smooth muscle, also relaxes, allowing urine to flow into the urethra, the tube that carries urine from the bladder out of the body. The detrusor muscle, which forms the wall of the bladder, contracts rhythmically to expel the urine. The entire process is controlled by the autonomic and somatic nervous systems, with conscious awareness and voluntary control playing a significant role, especially in adults.

Disruptions in micturition can lead to various medical conditions, including incontinence (involuntary leakage of urine) or retention (inability to empty the bladder). These issues can stem from neurological disorders, infections, structural abnormalities, or psychological factors. Understanding the mechanics of micturition is crucial for diagnosing and treating these urological problems.